The price of eggs and other food products is at the heart of the debate about an amendment to the farm bill, a gigantic piece of legislation passed by Congress every five years or so.

The bill is so big that some critics say it’s riddled with pork. But the 10th Amendment argument is about whether a state can decide to ban the sale of agricultural products if they aren’t produced in a manner approved by it.

And that’s where the eggs come into play.

Last week, a House committee approved an amendment proposed by Representative Steve King from Iowa. The amendment would prevent states from banning the sale of agriculture products from other states that don’t meet their standards for food production.

For example, California’s new egg law, which goes into effect in 2015, requires that chickens be kept in certain types of cages when they lay eggs. If the eggs come from chickens kept in smaller cages in other states, they can’t be sold in California. And that would obviously affect the price of eggs.

That’s where Representative King yells foul (or fowl).

“The Constitution of the United States reserves the regulation of interstate commerce to the Congress, not the states,” said King in a statement, alluding to the Commerce Clause in Article I of the Constitution. “By 2015, California will allow only eggs to be sold from hens housed in cages specified by California. The impact of their large market would compel producers in other states to invest billions to meet the California standard of ‘means of production.’”

King introduced a similar amendment in July 2012 that died along with the farm bill at the end of the last Congress.

Animal rights groups and a fellow Republican, Jeff Denham, from California, strongly oppose the King amendment.

“I think the constitutionality of this is very clear. In the ’70s, the court reasoned if Congress may withdraw from the states the authority to make certain decisions, there would be little left of the states’ separate and independent existence, or the 10th amendment at all,” Denham said in the moments before his efforts to defeat the King amendment failed.

The 10th Amendment simply reads, “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States, respectively, or to the people.”

If King’s invocation of the Commerce Clause sounds familiar, you’ll recall the ongoing debate about it last June, when a divided Supreme Court upheld President Obama’s Affordable Care Act.

Article I, Section 8, of the Constitution gives Congress the power “to regulate Commerce with foreign Nations, and among the several States.”

Last summer, King made the case for his amendment in an editorial for the National Cattlemen’s Beef Association.

“Our Founding Fathers understood states would erect trade barriers against each other. That is why the enumerated power of Congress, to exclusively regulate interstate commerce, is enshrined in our Constitution. They knew that if states were left to themselves, the temptation to erect trade barriers in an effort to protect the interests of the producers within their borders would be hard to overcome,” he said.

King says a state like California can offer products that meet its standards, and others, too, to give consumers a choice.

California’s law came in the aftermath of Proposition 2, which was passed by voters in 2008. It requires more space for cooped chickens living in the state by January 1, 2015. Then-Governor Arnold Schwarzenegger signed a companion law in July 2010 that requires all eggs sold in the state, regardless of their origin, to come from chickens living in similar cages.

In April, Senator Dianne Feinstein championed the Egg Products Inspection Act Amendments of 2013. It would create a national standard for egg-laying conditions based on the California standard. Other states would have until 2029 to comply with the new rules.

The act was backed by the United Egg Producers (which reportedly represents 88 percent of the industry) and the Humane Society of the United States, but it wasn’t included in a draft version of the farm bill in the Senate.

Another egg group, the Egg Farmers of America, is siding with King on the issue of regulation.

For now, the farm bill remains very much in the air, and action will not come on it until June. The House and Senate will need to agree on one bill that contains other controversial measures, like cuts to food credits to some consumers and crop subsidies.

Scott Bomboy is the editor-in-chief of the National Constitution Center.